A base station apparatus (a base station, a cell, a first communication apparatus (communication apparatus different from a terminal device), and eNodeB), and a terminal device (a terminal, a mobile terminal, a mobile station apparatus, a second communication apparatus (communication apparatus different from the base station apparatus), user equipment (UE), and a user device) are included in a communication system such as Wideband Code Division Multiple Access (WCDMA) (registered trademark), Long Term Evolution (LTE), and LTE-Advanced (LTE-A) by Third Generation Partnership Project (3GPP), and a Wireless Local Area Network (WLAN), and Worldwide Interoperability for Microwave Access (WiMAX) by The Institute of Electrical and Electronics engineers (IEEE). Each of the base station apparatus and the terminal device includes a plurality of transmit/receive antennae. The base station apparatus and the terminal device perform spatial multiplexing on a data signal by using a Multi Input Multi Output (MIMO) technology, and thus high-speed data communication is realized.
In 3GPP, in order to realize high-speed data communication between the base station apparatus and the terminal device, carrier aggregation (CA) in which simultaneous communication is performed by using a plurality of component carriers is employed (NPL 1).
In 3GPP, as a frame structure type of a bi-directional communication scheme (duplex communication scheme), frequency division duplex (FDD) and time division duplex (TDD) are employed. In FDD, a full duplex scheme in which bi-directional communication can be simultaneously performed, and a half duplex scheme in which uni-directional communication is switched and thus the bi-directional communication is realized are employed (NPL 2). There is also a case where LTE employing the TDD is referred to as TD-LTE or LTE TDD.
In 3GPP, TDD-FDD carrier aggregation (TDD-FDD CA) in which a component carrier (TDD carrier) which supports the TDD, and a component carrier (FDD carrier) which supports the FDD are aggregated and communication is performed is examined (NPL 3).